I attended a seminar today at Apple on integrating Mac OS X into a Windows network environment, and although much of the information was not new to me, one little snippet caught my attention, as we have been wanting to do this at work for a while.

To add a banner text message to the login window, edit the file /Library -> Preferences -> com.apple.loginwindow.plist as a superuser, and add the following just after the first <dict> tag:

<key>LoginwindowText</key>
<string>Your text goes here...</string>

When you log out, the text inside the section will be displayed under the Mac OS X logo, in a box the width of the login window. This is good for adding a standard notice about workplace or campus rules for computer usage.

A warning message about system usage prior to login was required at one of my previous employers; without the ugly text box, I'm not sure how I would have been able to use OS X at that office. So I consider the text box a BUBU feature .... Bloody Ugly But Useful!

In OS 10.4.2, the contents of the file /Library/Preferences/com.apple.loginwindow.plist are very few: a string of about 100 characters without tags. In particular, there is no key after which to insert:

I don't think it's ugly. The text is antialiased (which is more than you get on Windows) and you don't have to click an OK button to dismiss it (like Windows). Okay, it could maybe be centered, but I just put a few spaces at the beginning of the string and it balanced it out okay.

I like it. Of course, it would be better if your computer name remained on the panel... They shouldn't be mutually-exclusive!

I tried this several times while running OS X 10.2.4 and could not get
the changes in the .plist document to save. I ended up booting into Mac
OS 9.2.1 and typing the text into a Simpletext document, saving the file
as the prescribed filename which needed to be edited
(com.apple.loginwindow.plist). I then copied the new file into the
Library/Preference folder, replacing the old file. When I rebooted, I saw
the text added to the Login Window.
I added a long disclaimer which even required the system to include a
scroll bar on the screen, so lenght of the text does not seem to matter
very much.
Jerry

the problems you had saving may have been caused by insufficient permissions. try using terminal and sudo your way in with your favorite editor. (if anyone's lost, type "sudo pico " and drag the plist onto the terminal window)

This hint didn't work for me (running 10.2.1). However, if you are familiar with Apple's free Interface Builder, you can get a similar result by modifying the loginwindow nib directly.
Login as root and open the following nib file in Interface Builder:
/System/Library/CoreServices/SecurityAgentPlugins/loginwindow.bundle/Contents/Resources/English.lproj/login.nib
Now put a text field below the hostname field, and add any message you desire. With this method, you can easily center the text using Interface Builder's alignment features, and the hostname and your text message don't need to be mutually exclusive!

If English isn't your primary language on your Mac, you will need to look in your language specific directory instead of 'English.lproj' as indicated above. Also, if you have selected to have your login window display a list of users instead of the name and password fields, you will need to edit MultipleUsers.nib instead of login.nib as indicated above. As always, BACKUP the original nib file before making any modifications. Note that you can mess with other pieces of the login panel too (such as the images), although the program Visage makes that a lot easier (blatant plug by developer).

I was wrong in my earlier post, this hint does work for me. I hadn't read the hint carefully enough, and I edited loginwindow.plist instead of com.apple.loginwindow.plist in the same directory. If anybody else is having problems, you might want to see if you made the same mistake!

I can't seem to get this to work on Panther but was able to using Jaguar. Now I can't remember how I did it back in the day...
was it:

sudo pico /Library/Preferences/com.apple.loginwindow.plist

and then editing the contents to:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple$
<plist version="1.0">
<dict>
<key>noPasswordKey</key>
<false/>
LoginwindowText
This computer was brought to you by the letter A and the number 1
</dict>
</plist>

hmm no, all it does is 10.3 resets the file to the original when I switch to the login panel with FUS. Even adding it in using and tags doesn't seem to work either...
What am I doing wrong?

To clarify how this works (in Panther anyway, but I'm assuming this is true for Jaguar as well). Open the file (you'll most likely need to use sudo if you're planning on saving your changes) using your favorite command-line text editor. Then you need to add the lines:

Is there a way to insert returns into the text string? I have almost no experience with this sort of psuedo-programming stuff, but I assume there might even be a character that causes a return in the formatting. My goal is, like many others I assume, to have a bit of text offering a reward for return of my laptop if found, and I'd love for the name and address to have standard formatting:

name
address
city, state, zip
phone

I'll play around with it while waiting for a response, but please, chime in if you have any thoughts.

) and re-save the plist as either text or xml (it's binary by default since leopard or tiger). then enter your string as documented in the hint without line breaks.

then, using a hex editor such as HexEdit (as root, the same way as above), open your now non-binary plist and insert, into the hex code of the file, the sequence "0A" wherever you want a line break (without the quotes, obviously). that's a zero, not an "o".

you may have to resave your plist as a binary (i did) to make it work, but i'm not sure.

Is there a way to insert returns into the text string? I have almost no experience with this sort of psuedo-programming stuff, but I assume there might even be a character that causes a return in the formatting. My goal is, like many others I assume, to have a bit of text offering a reward for return of my laptop if found, and I'd love for the name and address to have standard formatting:

name
address
city, state, zip
phone

I'll play around with it while waiting for a response, but please, chime in if you have any thoughts.

Is there a way to insert returns into the text string? I have almost no experience with this sort of psuedo-programming stuff, but I assume there might even be a character that causes a return in the formatting. My goal is, like many others I assume, to have a bit of text offering a reward for return of my laptop if found, and I'd love for the name and address to have standard formatting:

name
address
city, state, zip
phone

I'll play around with it while waiting for a response, but please, chime in if you have any thoughts.

I used Interface Builder to put my info directly the Sleep, Restart, Shutdown buttons. I couldn't figure out how to input a return, so I used 5 seperate text fields to input the info. Took a bit pf playing around to get it the way I wanted, but it's done now. First, I made a new textfield, went to tools to show inspector. Under title, I input the info. Then, drag into position. Did copy, paste to get the next line, changed the info in title and so on.

My text:
"♬♪♩♫ This is a computer. You must authenticate if you wish to proceed. All actions will be logged. Do not drool, vomit, or otherwise expectorate on the computer. Do not submerge the computer in water. You will fail. Do not eat. Do not want. ♬♪♩♫"

I may be dense but using 10.4.10 when i pico /Library/Preferences/com.apple.loginwindow.plist all that is in the file is
"bplist00?^A^B^C^D^E^F^G^H]showInputMenu\lastUserName_^P^PRetriesUntilHintXlastU$"

Agreed. This simply doesn't work on 10.4.10. I get the same sort of text above. When I went to a machine that does have the custom login screen and copied the plist onto a 10.4.10 machine, it not only didn't give a custom message but it forced log in from entering username and password to showing you a list of users.

I don't know if it has anything to do with the fact that my Macs here are on both OD and AD. WOuld sure be nice if this worked.

The best way to edit system property lists is using the 'defaults' command. This is scriptable. I want a message in case my MacBook gets separated from me at airport security, and a per-system identifier to diagnose restart issues, so I use the script